[STORY]: add spinner & auto-refresh after uploading a file

Full User Story

As a cpf reporter user, after I upload a file, I want indicators that validation is in progress and I want to see results when they are ready.

Why is this issue important?

current state is that you can only see validation results if you refresh the page, so even when validation is complete, it shows the "validation in progress page." It is likely that users will think this is broken and try to upload the file again.

Action Plan

[ ] Initial design drafted
[ ] Initial acceptance criteria drafted
[ ] High level technical approach & feature flag use determined
[ ] Designs & Acceptance criteria finalized
[ ] Eng task breakout complete
[ ] Assessment of whether partner training & communication actions are needed
[ ] Acceptance criteria testing completed & passed in staging
[ ] Feature flags enabled in production
[ ] Feature flags are removed once the feature is deemed stable

Engineering Tasks

Add links to engineering tasks

Acceptance Criteria

After you upload and submit a file, on the validation in progress page, you should see a loading spinner. As soon as the validation results are ready, the results page should display without the user needing to reload the page.

usdigitalresponse / cpf-reporter